2N5089 Transistor Overview

The 2N5089 is a small signal NPN transistor in a TO-92 through-hole package. It is designed for low power applications with a maximum collector current of 50mA and a power dissipation of 500mW. The 2N5089 has a transition frequency of 300MHz, making it suitable for high frequency applications up to VHF.

2N5089 Transistor Key Features:

• NPN bipolar junction transistor
• TO-92 through-hole package
• Low power – max 50mA collector current
• Max power dissipation of 500mW
• High frequency response – 300MHz transition frequency
• General purpose amplifying and switching

2N5089 Transistor Pinout

The 2N5089 transistor has 3 pins in a TO-92 through-hole package. The following table shows the 2N5089 pinout with pin numbers and functions:

Pin Number	Pin Name	Description
1	Emitter	Emitter terminal of the NPN transistor
2	Base	Base terminal which controls collector current
3	Collector	Collector terminal where main current flows

When viewed from the bottom with leads pointing up, the 2N5089 pinout from left to right is: Emitter (E), Base (B), Collector (C).

2N5089 Transistor Specifications

Understanding the key specifications of the 2N5089 transistor is important for proper application. The absolute maximum ratings define the limits that must not be exceeded to prevent damage. Key electrical characteristics specify performance under defined operating conditions.

Absolute Maximum Ratings

Parameter	Symbol	Value	Unit
Collector-Base Voltage	V_CBO	60	V
Collector-Emitter Voltage	V_CEO	50	V
Emitter-Base Voltage	V_EBO	6	V
Collector Current	I_C	50	mA
Total Power Dissipation (T_a = 25°C)	P_D	500	mW
Operating and Storage Junction Temperature Range	T_J, T_stg	-55 to +150	°C

Electrical Characteristics (at T_a = 25°C unless otherwise noted)

Parameter	Symbol	Test Conditions	Min	Typ	Max	Unit
Collector-Emitter Breakdown Voltage	BV_CEO	I_C = 1mA	50			V
Collector-Base Cutoff Current	I_CBO	V_CB = 50V			100	nA
Emitter-Base Cutoff Current	I_EBO	V_EB = 6V			100	nA
DC Current Gain	h_FE	V_CE = 10V, I_C = 10mA	100	180	300
Collector-Emitter Saturation Voltage	V_CE(sat)	I_C = 10mA, I_B = 1mA		0.3	0.6	V
Base-Emitter On Voltage	V_BE(on)	V_CE = 10V, I_C = 10mA		0.7	0.85	V
Current-Gain – Bandwidth Product	f_T	V_CE = 10V, I_C = 5mA, f = 100MHz	300			MHz

For more detailed specifications, consult the official 2N5089 datasheet.

How to Use the 2N5089 Transistor

The 2N5089 transistor can be used in various amplifying and switching circuits. Two common applications are as a common emitter amplifier and as a switch. Here are examples of how to implement the 2N5089 in these circuits:

Common Emitter Amplifier

A common emitter amplifier provides voltage and current gain by using the transistor’s ability to control a large collector current with a small base current. Here is an example schematic:

The input signal is applied to the base through a coupling capacitor and bias resistor divider R1/R2. This sets the DC operating point. The AC signal varies the base voltage, controlling the collector current.

The amplified output signal is developed across collector resistor Rc and coupled to the load through C2. RE and CE provide emitter stabilization and bypass to prevent AC feedback and improve gain.

Transistor Switch

The 2N5089 can also function as an electronic switch by operating it in saturation or cutoff mode. When saturated by applying sufficient base current, V_CE is near 0V and the switch is “on”. When base current is removed, no collector current flows and V_CE rises to V_CC – the switch is “off”.

When the input signal exceeds V_BE(on) of 0.7V, base current flows through RB and turns the transistor on. Rc limits collector current. When the input is low, the transistor is off. The output will swing between about V_CC and V_CE(sat) as the switch turns on and off.

2N5089 Transistor Applications

With its general purpose characteristics, the 2N5089 is useful in many low power circuits, such as:

• Small signal audio amplifiers
• RF oscillators and mixers
• Sensor signal amplifiers
• Driver circuits for relays, buzzers, LEDs
• Logic level shifting and interfacing
• Constant current sources

The high frequency response also enables applications in wireless, IF amplifiers, and video circuits up to the VHF range.

Frequently Asked Questions (FAQ)

Q: What is the pinout of a 2N5089 transistor?

A: Viewed from the bottom with leads pointing up, the 2N5089 pinout is:
1. Emitter
2. Base
3. Collector

Q: How much current can a 2N5089 handle?

A: The maximum collector current rating of the 2N5089 is 50mA. The total power dissipation limit of 500mW at 25°C must also be observed.

Q: What is the 2N5089 used for?

A: The 2N5089 is a general purpose NPN transistor used for low power amplifying and switching applications up to 300MHz, such as in small signal audio amps, RF oscillators, sensor amps, relay/LED drivers, and logic circuits.

Q: Is the 2N5089 an NPN or PNP transistor?

A: The 2N5089 is an NPN bipolar junction transistor.

Q: What is the maximum operating frequency of the 2N5089 transistor?

A: The transition frequency (f_T) of the 2N5089 is 300MHz, so it can be used in applications up to the VHF frequency range. Gain decreases above f_T.

Conclusion

This article has provided a comprehensive guide to the 2N5089 transistor, including its pinout, key specifications, example circuits, and applications. With its general purpose NPN characteristics and decent high frequency performance, the 2N5089 is a go-to choice for many low power amplifying and switching needs. As always, be sure to review the complete datasheet for full specifications. Happy circuiting!